The first time I saw a picture of this little guy I thought
it had to be a photoshop thing; some little creature made up by some talented
artist. It made me want to delve deeper, and you know what I found - It really
does exist!
Believe it or not...it's pelagic
Believe it or not, this little sea slug or nudibranch, is
pelagic (lives in the open water). It is often found floating upside down on
the surface of the ocean in temperate and tropical waters in such regions as
the east and south coasts of South Africa, Mozambique, European waters, the
east coast of Australia, and the islands of Hawaii. They also have been spotted
in the waters of Bermuda.
When fully grown it's a whopping 3-4cm...
Its average size when fully grown is a whopping
3-4cm. The blue dragon's floating abilities are due to a gas-filled sac located
in its stomach. Because of its location, this sac causes the slug to float
upside down exposing its blue-white foot to the surface of the water, leaving
the silver-gray dorsal surface facing downward into the water. This is an
example of counter shading, where the coloration helps to protect the organism
from it predators both below and above. These slugs spend most of their lives
drifting along, directed by currents and winds. They are generally not observed
by humans except on those occasions when strong onshore winds bring masses of
them (often called the "blue fleet") to beaches, causing much pain
for swimmers and beach-goers.
Blue Dragons are cannibalistic
Common names for this beautiful slug are blue dragon, blue
glaucus, blue sea slug, blue ocean slug, and sea swallow. G. atlanticus is
carnivorous and preys on other, larger pelagic organisms such as the venomous
Portuguese Man o' War, the by-the-wind sailor, the blue button, and the violet
snail. They have also been known to become cannibalistic.
It's immune to the venom of a Portuguese Man o' War
The blue dragon is immune to the venomous nematocysts of the
Portuguese Man o' War, and when consuming this animal, appears to select and
store the most venomous nematocysts in specialized sacs called cnidosacs on the
tip of its feather-like fingers. Because it is able to store up this venom for
future use, ironically it can produce a more powerful and deadly sting than the
man 'o war upon which it feeds.
Blue Dragons are hermaphrodites...
Blue dragons are hermaphrodites (have both male and female
reproductive organs). After mating, both animals produce 4-6 egg strings within
an hour that float freely in the water or are placed on the remains of prey.
These busy little slugs can produce from 3300-8900 eggs per day.
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References:
1. Glaucus atlanticus Forster, 1777. World Register of Marine Species, accessed 3 April
2010.
2. "Marine Species
Identification Portal : Glaucus atlanticus".
Species-identification.org. http://species-identification.org/species.php?species_group=pelagic_molluscs&id=189. Retrieved
2011-11-21.
3. Rudman, W. B. (6 November
1998). "Glaucus
atlanticus Forster, 1777". Sea Slug
Forum. http://www.seaslugforum.net/factsheet.cfm?base=glauatla. Retrieved 26
February 2011.
4. Debelius, H.; Kuiter, R. H. (2007). Nudibranchs of the
world. IKAN-Unterwasserarchiv. ISBN 978-3-939767-06-0.
5. http://seaslugsofhawaii.com/species/Glaucus-atlanticus-a.html
6. http://www.thecephalopodpage.org/marineinvertebratezoology/glaucusatlanticus.html
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